**5. Conclusion**

*Type 2 Diabetes - From Pathophysiology to Cyber Systems*

\*VLF power

HF power

HF power

**Table 3.**

**Table 4.**

**Variable Unit Description Physiological correlates**

Mediated renin-angiotensin

PNS and SNS influences

system

"

"

#

#

PNS influences

**correlates**

PNS influences

SNS influences

ms2 Absolute power of the very-low-frequency band

(0.04–0.15 Hz) in normal units

ms2 Absolute power of the high-frequency band

Nu Relative power of the high-frequency band (0.15–0.4 Hz) in normal units

LF/HF % Ratio of LF to HF power Sympatho-vagal balance

**Variable Unit Description Physiological** 

SD1 Ms Poincaré plot standard deviation perpendicular the line of identity

SD2 Ms Poincaré plot standard deviation along the line of

identity

Reduced HRV is the earliest of sign CAN, reflecting impaired sympathetic and parasympathetic activity without apparent clinical signs and symptoms of CAN [29]. T2DM causes decrease in almost all HRV variables. In a systematic review and meta-analysis performed on 25 studies analyzing HRV in T2DM showed overall decrease in the HRV in patients with T2DM owing to reduction both sympathetic and parasympathetic nerve function [30]. In another systematic review done on eight studies showed SD1/SD2, SDANN, and HF to have more sensitivity and specificity to detect autonomic dysfunction in diabetic patients indicating their

SD1/SD2 % Ratio of SD1- to – SD2 power Sympatho-vagal balance

Abnormal nonlinear HRV variables are associated with diabetes or with the risk of development of T2DM [32]. Likewise, a review study revealed reduction in HRV variables, obtained through short-term and 24-hour ECG recording, in metabolic

There are no standard reference values for HRV variables to diagnose CAN [22]. However, Breder and Sposito proposes the diagnosis of CAN could be made on obtaining abnormal result in at least two of the following six parameters:

(0.0033–0.04 Hz)

LF peak Hz Peak frequency of the low-frequency band (0.04–0.15 Hz)

LF power ms2 Absolute power of the low-frequency band (0.04–0.15 Hz)

LF power Nu Relative power of the low-frequency band

HF peak Hz Peak frequency of the high-frequency band (0.15–0.4 Hz)

(0.15–0.4 Hz)

*Frequency domain variables of HRV with physiological significance.*

*\*It is not well defined in short-term recording.*

**4.2 HRV in type 2 diabetes mellitus**

*Non-linear variables of HRV and physiological significance.*

potentials to be better diagnostic markers [31].

syndrome and T2DM [29].

*"PNS AND SNS influences. #PNS influences.*

**302**

HRV displays beat-to-beat variations caused predominantly by the interplay of PNS and SNS control on SA node. Decline in HRV is seen even before manifesting signs and symptoms of diabetic CAN. Reduced HRV is the earliest sign of CAN. CAN is one of the under diagnosed microvascular complications of T2DM caused by hyperglycemia induced neuronal damage. Almost all HRV variables are decreased in T2DM.
